A wise man once told me that how much you eat determines how much you weigh, but it's
what you eat that determines your body composition.
So a 200lb person with 30% bf eats about the same amount as a 200lb person with 7% bf. The only difference is where those calories are coming from. (obviously this is a little bit of an exaggeration. no one could weigh 200lb at 7% bf without a well designed training program, im just making a point

)
The moral of the story here is that, as italianangel said, you are exercising more than enough. What needs changing is your diet. Don't eat less calories, just eat healthier foods. I'll bet your diet contains alot of junk food and alot of fast food. Is that a correct assumption? If so, then your problem can be easily solved.
Check out the nutrition forum, there's tons of info there, and post any questions you have.